The present disclosure relates to harvesting articulated (jointed) combines and more particularly to improved concaves in the forward tractor or crop processing power unit (PPU).
Most agricultural combines use a rotary threshing and/or separating system including at least one rotor drivingly rotated about a rotational axis within a rotor housing, the housing having a lower region including a perforated concave spaced radially outwardly of the rotor. The rotor often may have a frusto-conical inlet end having a helical flight or flights therearound for conveying a flow of crop material into the space between the rotor and the housing. The main body of the rotor typically will have an array or layout of threshing elements, most commonly including rasp bars and separating elements, and/or elongated tines, all of which protrude radially outwardly therefrom into the space. The rasp bars and separator bars are configured differently, so as to perform different functions and may not all be present on a given rotor design. The functions of the rasp bars include to cooperate with one or more vanes and guides typically disposed around the upper portion of the inner circumference of the rotor housing, for conveying a mat of the crop material along a generally helical path through the space, while cooperating with the vane or vanes and/or guides, and other aspects of the concave, e.g., bars, perforations and the like of the concave, to break up larger components of the crop material into its constituents, namely larger constituents or elements of crop residue commonly referred to as straw, which includes stalks, stems, cobs and the like, and smaller constituents which comprise the grain and smaller elements of material other than grain (MOG), in the well known manner.
Rasp bars usually are relatively narrow and generally concentrated nearer the inlet end of the rotor and include a plurality of serrations defining grooves in the threshing element. These grooves are oriented at small acute angles to, or generally aligned with, the direction of rotation of the rotor for raking or combing through the mat of crop material and uncoupling the smaller constituents from the crop material thus allowing the grain to fall through the openings in the concave. Straight separator bars, in contrast, are often longer and generally located nearer to the discharge end of the rotor and include one or more bars with at least one sharp edge extending perpendicular to the direction of rotation to plow the larger components of the crop mat and carry them away from the smaller grain and MOG. The function of typical straight bars is to disrupt the consistent flow that shorter rasp bars establish and, thereby, cause grain to be shaken out of the straw due to that turbulence.
Application Ser. No. 14/967,691, now U.S. Pat. No. 9,820,442, disclosed a rotor and cage assembly that includes a skeleton of curved spaced-apart side members affixed to laterally extending horizontal (upper and lower) spaced-apart members therebetween and surrounding the rotor. One of the curved spaced-apart side members is terminated with curved fingers. Three concave inserts insert laterally into the skeleton spanning 270° around the rotor. One of the concave inserts carries straight fingers that interlace between the skeleton side member curved fingers. A control assembly of plates having arcuate slots placed at 3 of the pivots of the skeleton assembly, control bars connected to the skeleton pivots, and an actuator connect to the control bars at one end effect arcuate rotation of the control bars resulting in the synchronized rotation of the arcuate slotted plates so that the interlaced straight fingers move closer together or farther apart with the fixed skeleton assembly curved fingers for different types of grain. The interlacing and overlapping concave inserts permit the three sections of 270° degree wrap to expand and contract their combined circumference as the concaves move nearer and farther from the rotor swung diameter. This movement is necessary in order to adjust to various crops and conditions, specifically and intentionally to prevent wide gap spaces between concave inserts especially when the assembly is in its open position. A reasonably identical grate assembly, which may or may not allow adjustment, follows and is adjacent to the concaves skeleton and also surrounds the rotor. Of course, the number of concave inserts could be greater or lesser in number and extend to less or more than 270°. For present purposes, the two different sets of fingers “interlace” both by being laterally offset (side-to-side), but also by being vertically offset (up-and-down). The key for interlaced fingers is that they move closer together and further apart for different types of grains.
In the current disclosure, the control system that interconnects each of the 3 sections has been replaced by individual control for each section.